JP2013528720A - Process for extracting mineral oil using surfactants based on butylene oxide-containing alkyl alkoxylates - Google Patents

Abstract

The present invention provides a method for extracting the mineral oil using the Winsor type III microemulsion flooding, the general formula _{^{R 1 -O- (D) n -}} (B) m - (A) l -XY - M ^An aqueous surfactant formulation comprising ⁺ at least one ionic surfactant is injected into a mineral oil deposit through an injection hole and crude oil is extracted from the deposit through an output hole. The invention further relates to an ionic surfactant of this general formula.
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Description

The present invention provides a method for extracting the mineral oil using the Winsor Type III microemulsion flooding, the general formula _{^{R 1 -O- (D) n -}} (B) m - (A) l -XY - M ⁺
A method for injecting an aqueous surfactant formulation comprising at least one ionic surfactant into a mineral oil deposit through an injection hole and removing crude oil from the deposit through an output hole. The invention further relates to ionic surfactants of this general formula and to a process for producing them.

  In natural mineral oil deposits, mineral oil is present in porous storage rock cavities, which are sealed to the soil surface by an impervious top layer. The cavities are very fine cavities, capillaries, holes, or the like. The fine hole neck (fine hole constriction) may have a diameter of only 1 μm, for example. In addition to mineral oil containing natural gas, the sediment contains water with more or less salt content.

  In the extraction of mineral oil, a distinction is made between primary, secondary and tertiary extraction. In the primary extraction, mineral oil flows through the holes after starting the drilling of the deposit due to the self-generated pressure of the deposit.

  Therefore, secondary extraction is performed after primary extraction. In the secondary extraction, in addition to the borehole responsible for the extraction of mineral oil, so-called production holes, further holes are drilled in the mineral oil-containing structure. In order to maintain the pressure or increase the pressure, water is injected into the deposit through these so-called injection holes. As a result of the water injection, the mineral oil is slowly moved through the structure through the cavity (progressing from the injection hole and towards the production hole). However, this works as long as the cavity is completely filled with oil and the higher viscosity oil is pushed forward by the water. When fluid water is interrupted by the cavity, the water immediately flows from this point through the least resistive passage, i.e. through the formed passage and no longer pushes the oil forward.

  Primary and secondary extractions usually extract only about 30-35% of the mineral oil present in the sediment.

It is known that the yield of mineral oil can be increased by using tertiary extraction. A review of tertiary oil extraction can be found, for example, in “Journal of Petroleum Science of Engineering 19 (1998)”, pages 265-280. Tertiary oil withdrawal includes, for example, a thermal process in which hot water or steam is injected into the deposit. This reduces the viscosity of the oil. The fluid medium used may likewise be a gas such as CO ₂ or nitrogen.

  Tertiary mineral oil extraction also includes methods where appropriate chemicals are used as an aid for oil extraction. This affects the location facing the end of the water stream and, as a result, can be used to extract mineral oil that has been held firmly in the rock structure so far.

  Around the end of the secondary extraction, viscous and capillary forces act on the mineral oil trapped in the pores of the sedimentary rock. The ratio of these two forces is determined by microscopic oil separation relative to each other. A dimensionless parameter, the so-called capillary number, is used to describe the action of these forces. This is the ratio of viscous force (velocity x viscosity of the phase on which the force acts) to capillary force (oil-water interfacial tension x rock wetting):

  In this equation, μ is the viscosity of the fluid that moves the mineral oil (petroleum), ν is the Darcy speed (flow rate per unit area), σ is the interfacial tension between the liquid that moves the mineral oil and the mineral oil, and θ is the mineral oil. And the contact angle between the rock and the rock (C. Melrose, CF Brandner, J. Canadian Petr. Tech. 58, Oct.-Dec., 1974). When the number of capillaries (capillary number) is high, the mobilization property of oil increases, and therefore the degree of oil extraction increases.

The number of capillaries at the end of secondary oil withdrawal is known to be in the range of about 10 ⁻⁶ and capillaries from about 10 ⁻³ to 10 ⁻² to mobilize additional mineral oil. It is necessary to increase the number.

For this purpose, it is possible to carry out a specific form of the flooding method known as Winsor type III microemulsion flooding. In Winsor type III microemulsion flooding, the injected surfactant forms a Winsor type III microemulsion with the water phase and the oil phase present in the sediment. The Winsor type III microemulsion is not a particularly small droplet emulsion, but a thermodynamically stable mixture of water, oil and surfactant. These three advantages are:
A very low interfacial tension σ between the mineral oil and the aqueous phase is achieved,
-This usually has a very low viscosity and as a result is not trapped in the porous matrix;
-It is formed with minimal energy introduction and can remain stable over a very long period of time (contrast emulsions, in contrast, have high shear forces that do not occur primarily in reservoirs) And is only kinetically stabilized).

Winsor type III microemulsion is in equilibrium with excess water and excess oil. Under these conditions of the microemulsion formulation, the surfactant covers the oil-water interface and lowers the interfacial tension σ, more preferably to a value of <10 ⁻² mN / m (very low interfacial tension). ). For optimum results, the proportion of microemulsion in a water-microemulsion-oil system with a defined proportion of surfactant should be maximal in nature. This is because a lower interfacial tension is achieved.

  In this way, the oil droplets can be changed (the interfacial tension between oil and water is reduced to a certain degree, so that a minimal interfacial surface is no longer required and the spherical shape is Are no longer preferred), and they can be driven (extruded) through the opening of the capillary tube by flooding water.

  If all the oil-water interface is covered with surfactant, a Winsor type III microemulsion is formed in the presence of an excess amount of surfactant. This therefore constitutes a reservoir for the surfactant, causing a very low interfacial tension between the oil and water phases. Due to the low viscosity Winsor type III microemulsion, it moves through the porous sedimentary rock in the flooding process (in contrast, the emulsion is trapped in the porous matrix and occludes the deposit). When the Winsor type III microemulsion encounters an oil-water interface that is not yet covered with surfactant, the surfactant from the microemulsion significantly reduces the interfacial tension of this new interface and (eg, oil Mobilization of the oil (by deformation of the droplets).

The oil droplets can then be combined into a continuous oil bank. This has two steps:
First, when a continuous oil bank passes through a new porous rock, the oil drops present there can merge with the bank.

  Furthermore, the oil droplets combine to form an oil bank, thereby reducing the oil-water interface and thus no longer needing to release the surfactant again. Thus, the released surfactant can mobilize oil droplets remaining in the formulation, as described above.

  Accordingly, Winsor type III microemulsion flooding is a very effective method and requires very little surfactant compared to the emulsion flooding method. In microemulsion flooding, the surfactant is typically optionally injected with a co-solvent and / or a basic salt (optionally in the presence of a chelating agent). A concentrated (thickened) polymer solution is then injected for mobility control. In a further variation, a mixture of thickening polymer and surfactant, co-solvent, and / or basic salt (optionally with a chelating agent) is injected and then the thickening polymer The solution is injected for mobility control. These solutions are usually clear to prevent blockage of the reservoir.

The conditions required for surfactants for tertiary mineral oil extraction are significantly different from those required for surfactants for other applications: the appropriate interface for tertiary oil extraction. The activator reduces the interfacial tension between water and oil (typically about 20 mN / m) to less than 10 ⁻² mN / m (to allow sufficient mobilization of the mineral oil). Should. This is done in the presence of a normal deposition temperature of about 15 ° C. to 130 ° C. and water with a high salt content, more particularly in the presence of a high proportion of calcium and / or magnesium ions. There must be. The surfactant must therefore be soluble in sediment water with a high salt content.

  In order to meet these requirements, mixtures of surfactants, particularly mixtures of anionic and nonionic surfactants, have often been proposed.

Patent Document 1 (US3890239), and organic sulfonates, and alkoxylates of C ₈ -C ₂₀ -AO-H type (AO = alkylene oxide having 2 to 6 carbon atoms), C ₈ -C ₂₀ -AO- discloses a combination of sulfate or C ₈ -C ₂₀ -AO- sulfonate type anionic surfactant. In patent document 1 (US3890239), description of alkylene oxide is only a very general thing. On the other hand, only the examples including EO are described.

Patent Document 2 (US Pat. No. 4,446,697) describes a method of using a C ₁ -C _6- (AO) _1-40 -EO _{≧ 10} -H type alkyl alkoxylate in combination with an anionic surfactant. AO may be 1,2-butylene oxide or 2,3-butylene oxide.

  Patent Document 3 (US Pat. No. 4,460,481) describes alkylaryl sulfate or sulfonate type surfactants. The alkylene oxide can be ethylene oxide, propylene oxide or butylene oxide. There is a condition that ethylene oxide constitutes the main part of alkylene oxide. No further details about butylene oxide are given.

  The parameters of use, such as the type of surfactant used, the concentration, and the mixing ratio are mutually dependent on the conditions (e.g. temperature and salt content) present in a given oil formulation by those skilled in the art. Adjusted according to quantity).

  As mentioned above, mineral oil production is proportional to the number of capillaries. This is higher when the interfacial tension between oil and water is low. If the average number of carbon atoms in crude oil is high, it will be difficult to lower the interfacial tension. Suitable surfactants for low interfacial tension are those with long alkyl groups. When the alkyl group becomes longer, it becomes easier to reduce the interfacial tension. However, the usability of such compounds is limited.

US3890239 US4448697 US4460481

  Accordingly, it is an object of the present invention to provide a surfactant that is particularly effective for use in surfactant flooding and to provide an improved method for tertiary mineral oil extraction. .

Accordingly, a method for performing tertiary mineral oil extraction using Winsor type III microemulsion flooding, wherein an aqueous surfactant formulation comprising at least one ionic surfactant is added to at least one injection. Injected into the mineral oil deposit through the pores, the interfacial tension between oil and water is <0.1 mN / m, preferably <0.05 mN / m, more preferably <0.01 mN / m Reducing the value and removing the crude oil from the deposit through at least one production hole,
Wherein the surfactant formulation, the general formula _{^{R 1 -O- (D) n -}} (B) m - (A) l -XY - M +
(However,
R ¹ is a linear or branched, saturated or unsaturated, aliphatic and / or aromatic hydrocarbon group having 8 to 30 carbon atoms,
A is ethyleneoxy,
B is propyleneoxy, and D is butyleneoxy,
l is 0 to 99;
m is 0-99, and n is 1-99,
X is an alkyl or alkylene group having 0 to 10 carbon atoms,
M ⁺ is a cation, and Y ⁻ is selected from the group of sulfate group, sulfonic acid group, carboxylate group, and phosphate group)
At least one surfactant, and the groups A, B and D may be randomly or alternately distributed, or two, three, four or more blocks of any sequence Wherein the sum of l + m + n ranges from 3 to 99 and the proportion of 1,2-butylene oxide is at least 80% relative to the total amount of butylene oxide.

  There is further provided a surfactant mixture (for mineral oil extraction) comprising at least one ionic surfactant as defined above.

The present invention is described in detail below;
In the process according to the invention (described above) for the extraction of mineral oil using Winsor type III microemulsion flooding, an aqueous surfactant formulation comprising at least one surfactant of this general formula is used. Is done. This may additionally contain further surfactants and / or other ingredients.

  In the method according to the present invention for conducting tertiary mineral oil extraction using Winsor type III microemulsion flooding, the interfacial tension between oil and water is <0 by using the surfactant of the present invention. It is reduced to a value of .1 mN / m, preferably <0.05 mN / m, more preferably <0.01 mN / m. Therefore, the interfacial tension between oil and water is a value in the range of 0.1 mN / m to 0.0001 mN / m, preferably a value in the range of 0.05 mN / m to 0.0001 mN / m, more preferably 0. Reduced to a value in the range of .01 mN / m to 0.0001 mN / m.

The at least one surfactant has the general formula _{^{R 1 -O- (D) n -}} (B) m - (A) l -XY - may be included in the M ^+. As a result of manufacture (preparation), a plurality of different surfactants of this general formula can also be present in the surfactant formulation.

The radical R ¹ is straight-chain or branched and has 8 to 30 carbon atoms, preferably 9 to 30 and particularly preferably 10 to 28 carbon atoms, aliphatic and / or Or it is an aromatic hydrocarbon group.

According to a particularly preferred embodiment of the invention, the group R ¹ is a commercially available fatty alcohol mixture composed of iso-C ₁₇ H ₃₅ — or linear C ₁₆ H ₃₃ — and C ₁₈ H ₃₇ —, or commercially available Derived from C ₁₆ -Guerbet alcohol 2-hexyldecyl-1-ol, or derived from commercially available C ₂₄ -Guerbet alcohol 2-decyl-tetradecanol, or commercially available C ₂₈ -Guerbet alcohol 2 -Derived from decyl-hexadecanol.

  Particularly preferably, for linear alcohols, n = 3 to 10 and m = 5 to 9, while for branched alcohols, n = 2 to 10 and m = 5 to 9. Here, preferably each is greater than 80%, 1,2-butylene oxide, and the alkyl oleoxide has a DBA sequence starting from an alcohol. Alkylene oxide is placed in the block in excess of 90%.

  Particularly preferred are linear or branched aliphatic hydrocarbon groups having 10 to 28 carbon atoms.

  The branched aliphatic hydrocarbon group usually has a degree of branching of 0.1 to 5.5, preferably 1 to 3.5. Here, the concept of “degree of branching” is defined as a value obtained by subtracting 1 from the number of methyl groups in the alcohol molecule in a known manner and method in principle. The average degree of branching is a statistical average value of the degree of branching of all molecules in the sample.

  In the above formula, A means ethyleneoxy. B means propyleneoxy and D means butyleneoxy.

In the above general formula, l, m and n mean integers. It will be clear to those skilled in the art of polyalkoxylates that these definitions are for individual surfactants (tensides). When a surfactant mixture or a surfactant formulation (containing a plurality of surfactants of this general formula) is present, the numbers l, m and n mean the average of all molecules of the surfactant. This is because in the alkoxylation of alcohols with ethylene oxide and / or propylene oxide and / or butylene oxide, a certain distribution occurs in the chain length. These distributions are represented in principle in a known manner by polydispersity D. D = M _w / M _n is the molecular weight (molar mass) divided by the molecular weight number average. Polydispersity can be measured by methods known to those skilled in the art, such as gel permeation chromatography.

  In the above formula, l means a number from 0 to 99, preferably a number from 1 to 40, particularly preferably a number from 1 to 20.

  In the above general formula, m means a number from 0 to 99, preferably a number from 1 to 20, and particularly preferably a number from 5 to 9.

  In the above general formula, n means a number of 1 to 99, preferably a number of 2 to 30, and particularly preferably a number of 2 to 10.

  According to the invention, the sum of l + m + n is a number in the range 3 to 99, preferably 5 to 50, particularly preferably 8 to 39.

  According to the invention, the proportion of 1,2-butyleneoxy is at least 80%, preferably at least 85%, preferably at least 90%, particularly preferably at least 95%, based on the total amount of butyleneoxy (D). 1,2-butyleneoxy.

  The ethyleneoxy- (A), propyleneoxy- (B), and butyleneoxy group (D) are randomly (statistically) distributed, alternately distributed (distributed), or 2, 3, 4, or More than this, the arrangement is in an arbitrary block state.

According to a preferred embodiment of the present invention, the order of R ¹ , butyleneoxy block, propyleneoxy block, ethyleneoxy block is preferred in the presence of a plurality of different alkyleneoxy blocks. The butylene oxide used should contain ≧ 80% 1,2-butylene oxide, preferably> 90% 1,2-butylene oxide.

  In the general formula described above, X is an alkylene group having 0 to 10, preferably 0 to 3 carbon atoms, or an alkenylene group. Preferably, the alkylene group is a methylene-, ethylene-, or propylene group.

In the cited prior art, there is often no specific description of the C ₄ -epoxide description. This can usually be understood to be 1,2-butylene oxide, 2,3-butylene oxide, iso-butylene oxide, and mixtures of these compounds. The composition usually depends on the C ₄ -olefin used and to some extent on the oxidation process.

  In the general formula described above, Y is a sulfonic acid group, a sulfate group, a carboxyl group, or a phosphate group.

In the above formula, M ⁺ is a cation, preferably selected from the group consisting of Na ⁺ ; K ⁺ , Li ⁺ , NH ₄ ⁺ , H ⁺ , Mg ²⁺ and Ca ²⁺ .

Surfactants according to this general formula can in principle be produced in a known manner by alkoxylation of the corresponding alcohol R ¹ —OH. The practice of such alkoxylation is known in principle to those skilled in the art. It is also known to those skilled in the art that the reaction mass, particularly the choice of catalyst, affects the molar mass distribution of the alkoxylate.

Surfactants according to this general formula are preferably prepared by alkoxylation using a basic catalyst. In this case, the alcohol R ¹ —OH can be inserted into the pressure vessel together with an alkali metal hydroxide, preferably potassium hydroxide, or an alkali metal alkoxide, such as sodium methoxide. Water present in the mixture can be removed under reduced pressure (eg <100 mbar) and / or elevated temperature (30-150 ° C.). Thereafter, the alcohol is present as the corresponding alkoxide. Next, it is deactivated using an inert gas (eg nitrogen) and the alkylene oxide (including multiple types) is stepped at a temperature of 60-180 ° C. and a maximum pressure of 10 bar or less. Added. According to a preferred embodiment of the invention, the alkylene oxide is metered in at 130 ° C. at the start. In the course of the reaction, the temperature rises to 170 ° C. due to the heat of reaction released. In a further preferred embodiment of the invention, butylene oxide is first added at a temperature in the range of 135 to 145 ° C, then propylene oxide is added at a temperature in the range of 130 to 145 ° C, and then ethylene oxide is 125. Added at a temperature in the range of ~ 145 ° C. At the end of the reaction, the catalyst can be centrifuged by adding an acid (eg acetic acid or phosphoric acid) and filtered if necessary.

However, alkoxylation of the alcohol R ¹ —OH can also be carried out using other methods, for example acid-catalyzed alkoxylation. Furthermore, double hydroxide clays can be used as described in DE 4325237 A1, or double metal cyanide catalysts (DMC catalysts) can be used. Suitable DMC catalysts are disclosed, for example, in DE 10243361 A1, in particular paragraphs [0029] to [0041] and the references cited therein. For example, a Zn-Co type catalyst can be used. To carry out the reaction, the alcohol R ¹ —OH can be mixed with the catalyst and the mixture can be dehydrated as described above and reacted with the alkylene oxide as described above. Typically, 1000 ppm or less of catalyst is used for the mixture, and because of this small amount, the catalyst can remain in the product. The amount of catalyst is usually less than 1000 ppm, for example 250 ppm or less.

  Anionic groups are finally used. This is in principle known to those skilled in the art. In the case of sulfate groups, for example, the reaction with sulfuric acid, chlorosulfuric acid or sulfur trioxide can be carried out in a falling film reactor and then neutralized. In the case of sulfonic acid groups, for example, the reaction with propane sultone can be carried out and then neutralized, the reaction with butane sultone can be carried out and then neutralized with vinyl sulfonic acid sodium salt The reaction can be carried out or the reaction with 3-chloro-2-hydroxypropanesulfonic acid sodium salt can be carried out. In the case of carboxylate groups, for example, the alcohol can be oxidized using oxygen and then neutralized, or the reaction with sodium chloroacetate can be carried out.

Additional surfactants In addition to the surfactants of this general formula, the formulation can optionally additionally comprise additional surfactants. These are, for example, alkylaryl sulfonates, or olefin sulfonate (alpha-olefin, or internal olefin sulfonate) type anionic surfactants and / or alkyl ethoxylate or alkyl polyglucoside type nonionic surfactants. These further surfactants may in particular be oligomeric or polymeric surfactants. Such polymeric co-surfactants are advantageously used to reduce the amount of surfactant required to form a microemulsion. Such polymeric co-surfactants are therefore also referred to as “microemulsion boosters”. Examples of such polymeric surfactants include amphiphilic block copolymers comprising at least one hydrophilic block and at least one hydrophobic block. Examples are polypropylene oxide-polyethylene oxide block copolymers, polyisobutylene-polyethylene oxide block copolymers, and comb polymers having polyethylene oxide side chains and a hydrophobic backbone (the backbone is preferably essentially olefin or (meth) Acrylate as a monomer). The term “polyethylene oxide” here includes in each case a polyethylene oxide block comprising propylene oxide as defined above. Further details of such surfactants are disclosed in WO 2006/131541 A1.

Process for Mineral Oil Extraction In the process according to the invention for mineral oil extraction, a suitable aqueous formulation of this general formula surfactant is passed through at least one injection hole in the mineral oil deposit. And the crude oil is removed from the deposit through at least one production hole. Here, the term “crude oil” naturally does not mean a single layer oil, but rather a normal crude oil-water emulsion. Usually, the deposit (deposition bed) is provided with a plurality of injection holes and a plurality of output holes.

  The main effect of the surfactant is to significantly reduce the interfacial tension between water and oil-desirably to a value of <0.1 mNm. By injecting the surfactant formulation, followed by water into the formulation (“water flooding”), as known as “surfactant flooding”, or preferably Winsor type III “microemulsion flooding” Alternatively, the pressure can be maintained by injecting a highly viscous aqueous solution of a polymer that preferably has a strong thickening action (“polymer flooding”). However, techniques are also known by allowing the surfactant to act on the formulation first. A further known technique is a technique in which a solution of a surfactant and a thickening polymer is injected, and then a solution of the thickening polymer is injected. One skilled in the art knows the performance of “surfactant flooding”, “water flooding” and “polymer flooding” and uses the appropriate technique according to the type of deposit.

  For the process according to the invention, an aqueous formulation comprising a surfactant of this general formula is used. In addition to water, the formulation may optionally include water miscible or at least one water dispersible organic material, or other material. Such additives act in particular to stabilize the surfactant solution during storage or during transport to the oil field. However, the amount of such additional solvent should normally not exceed 50% by weight and preferably not exceed 20% by weight. In a particularly advantageous embodiment of the invention, exclusively water is used for the formulation. Examples of water miscible solvents include alcohols such as methanol, ethanol, and propanol, butanol, sec-butanol, pentanol, butylethylene glycol, butyldiethylene glycol, or butyltriethylene glycol.

  According to the present invention, the proportion of surfactant of this general formula is at least 30% by weight relative to all the surfactant present (ie the surfactant of this general formula and optionally present). %. This proportion is preferably at least 50% by weight.

  The mixture used according to the invention can preferably be used for surfactant flooding of the deposit. This is particularly appropriate for Winsor type III microemulsion flooding (Winsor type III range or flooding in the presence of a bicontinuous microemulsion phase). The technique of microemulsion flooding has already been described in detail above.

In addition to the surfactant, the formulation may contain further ingredients such as C _4-to C ₈ alcohols and / or basic salts (so-called “alkaline surfactant flooding”). Such additives are used, for example, to reduce retention in the formulation. The ratio of alcohol to the total amount of surfactant used is usually at least 1: 1, however, a considerable excess of alcohol can also be used. The amount of basic salt is typically in the range of 0.1% to 5% by weight.

  The deposit to which the method is applied has a temperature of at least 10 ° C, such as 10 to 150 ° C, preferably at least 15 ° C to 120 ° C. The total concentration of all surfactants together is 0.05-5% by weight, preferably 0.1-2.5% by weight, based on the total amount of aqueous surfactant formulation. Those skilled in the art will make an appropriate selection according to the desired properties, in particular the conditions of the mineral oil formation (mineral oil structure). Here, it is clear to those skilled in the art that the concentration of the surfactant changes after injection into the formation (structure). This is because the formulation is miscible with formation water or the surfactant can be absorbed onto the solid surface of the formation. It is a great advantage for the mixtures used according to the invention that the surfactants reduce the interfacial tension particularly well.

  It is naturally possible and recommended to first produce a concentrate (the concentrate is diluted in situ only to the desired concentration for injection into the formation). Usually, the total concentration of surfactants in such concentrates is 10 to 45% by weight.

  The following examples illustrate the invention in detail:

Part I: Synthesis of Surfactants Common Method 1: Alkoxylation Using KOH Catalyst (Effective for Use of KOH, PO and / or BuO) Alcohol to be alkoxylated (1.0 eq) in a 2 l autoclave It mixed with the KOH aqueous solution containing 50 mass% KOH. The amount of KOH is 0.2% by weight of the product to be produced. During stirring, dehydration was carried out at 100 ° C. and 20 mbar for 2 hours. It was then purged 3 times using N ₂ to establish a feed pressure of about 1.3 bar of N ₂ and a temperature rise of 120-130 ° C. Maintain the temperature in the range 125 ° C to 135 ° C (for ethylene oxide), 130 ° C to 140 ° C (for propylene oxide), or 135 to 145 ° C (for 1,2-butylene oxide). The alkylene oxide was metered in. The mixture was then stirred at 125-145 ° C. for an additional 5 hours, purged with N ₂ , cooled to 70 ° C., and the reactor was emptied. The basic crude product was neutralized using acetic acid. Alternatively, neutralization can be performed by using commercially available magnesium silicate and then filtering off. ¹ H NMR spectra in CDCl ₃ , gel permeation chromatography, and OH number measurements were used to characterize the pale product and determine yield.

Common method 2: alkoxylation using DMC catalyst in the case of 2,3-butylene oxide In a 2 l autoclave, the alcohol to be alkoxylated (1.0 eq) is converted to a double metal cyanide catalyst (for example Zn-- from BASF). Co type DMC catalyst) at 80 ° C. In order to activate the catalyst, a pressure of about 20 mbar was applied at 80 ° C. for 1 hour. The amount of DMC is less than 0.1% by weight of the product produced. It was then purged 3 times using N ₂ to establish a feed pressure of about 1.3 bar of N ₂ and a temperature rise of 120-130 ° C. Maintain the temperature in the range 125 ° C to 135 ° C (for ethylene oxide), 130 ° C to 140 ° C (for propylene oxide), or 135 to 145 ° C (for 2,3-butylene oxide). The alkylene oxide was metered in. The mixture was then stirred at 125-145 ° C. for an additional 5 hours, purged with N ₂ , cooled to 70 ° C., and the reactor was emptied. ¹ H NMR spectra in CDCl ₃ , gel permeation chromatography, and OH number measurements were used to characterize the pale product and determine yield.

Common Method 3: Sulfation Using Chlorosulfonic Acid In a 1 l round bottom flask, the alkylated alkoxylate (1 eq) to be sulfated is dissolved in 1.5 times the amount of dichloromethane (based on weight percent). And cooled to 5-10 ° C. Thereafter, chlorosulfonic acid (1.1 eq) was added dropwise such that the temperature did not exceed 10 ° C. The mixture was allowed to warm to room temperature and stirred at this temperature for 4 hours under N ₂ flow (before the above reaction mixture was added dropwise and added to half volume NaOH aqueous solution at a maximum of 15 ° C.). The amount of NaOH was calculated to be slightly in excess based on the chlorosulfonic acid used. The resulting pH is about pH 9-10d. Dichloromethane was removed at maximum 50 ° C. (using a rotary evaporator under mild vacuum).

¹ HNMR was used to characterize the product and measure the water content of the solution (approximately 70%).

The following alcohols were used for the synthesis:

Performance Test In order to evaluate the stability for extracting tertiary mineral oil, the following tests were conducted using the obtained surfactant.

Explanation of test method Measurement of SP ^* a) Measurement principle:
The interfacial tension between water and oil was measured in a known manner via measurement of the solubilization parameter SP ^* . Measurement of interfacial tension via measurement of solubilization parameter SP ^* is an accepted method of measuring interfacial tension, accepted in the art. The solubilization parameter SP ^* represents the ml of oil dissolved per ml of surfactant used in the microemulsion (Winsor type III). If equal amounts of water and oil are used, the interfacial tension σ (IFT) can be calculated from this using the approximate formula IFT≈0.3 / (SP ^* ) ² (C.I. Huh, J. Coll. Interf. Sc., Vol. 71, No. 2 (1979)).

b) Procedure To measure SP ^* , a 100 ml measuring cylinder equipped with a magnetic stir bar is filled with 20 ml oil and 20 ml water. To this is added a specific surfactant concentrate. Next, the temperature is raised stepwise from 20 to 90 ° C. and a temperature window in which a microemulsion is formed is observed.

Microemulsion formation can be assessed visually or otherwise using conductivity measurements. A three-phase system is formed (upper oil phase, middle microemulsion phase, lower aqueous phase). If the upper and lower phases are of equal size and do not change over a 12 hour period, the optimum temperature (T _opt ) of the microemulsion is found. The volume of the intermediate phase is measured. The volume of surfactant added is subtracted from this volume. The resulting volume is then divided by 2. This volume is then divided by the volume of surfactant added. What was obtained is described as SP ^* .

The type of oil and water used to measure SP ^* is determined according to the system being tested. It is possible to use the mineral oil itself or a model oil such as decane. The water used may be pure water or salt water (to better model conditions in mineral oil formulations). For example, the composition of the aqueous phase can be adjusted according to the composition of the particular deposition water.

  Information about the aqueous phase used and the oil phase can be found in the description of the test below.

Test Results A 1: 1 mixture of decane and NaCl solution was mixed with butyldiethylene glycol (BDG). Butyl diethylene glycol (BDG) functions as a cosolvent and is not included in the calculation of SP ^* . To this was added a surfactant mixture (Lutensit A-LBN 50 ex BASF) consisting of 3 parts alkyl alkoxy sulfate and 1 part dodecylbenzene sulfonate. The total surfactant concentration was reported as a percentage by mass of the total volume. In a further test, a 1: 1 mixture of decane and sodium chloride was mixed with butyl diethylene glycol (BDG). Butyl diethylene glycol (BDG) acted as a co-solvent and was not considered for SP ^* . A surfactant mixture (Hostapur SAS 60 ex Clariant) consisting of 3 parts alkyl alkoxy sulfate and 1 part secondary alkyl sulfonate was added. The total surfactant concentration was given as a percentage by weight of the aqueous phase.

In addition, a 1: 1 mixture of South German crude oil (API 33 °) and NaCl solution was mixed with butyldiethylene glycol (BDG). Butyl diethylene glycol (BDH) functions as a co-solvent and is not included in the calculation of SP ^* . To this was added a surfactant mixture (Lutemitit A-LBN 50 ex BASF) consisting of 3 parts alkyl alkoxy sulfate and 1 part dodecylbenzene sulfonate. Total surfactant concentration was reported as a percentage by mass of the total volume.

In two further tests, a 1: 1 mixture of crude oil (API 33 °) and sodium chloride solution from southern Germany, or a 1: 1 mixture of crude oil Canada (API 14 °) and sodium chloride solution, respectively, was butyldiethylene glycol (BDG). Mixed with. Butyl diethylene glycol (BDG) acted as a co-solvent and was not considered for SP ^* . A surfactant mixture (Hostapur SAS 60 ex Clariant) consisting of 3 parts alkyl alkoxy sulfate and 1 part secondary alkyl sulfonate was added, respectively. Each total surfactant concentration is given as a percentage by weight of the aqueous phase.

  The results for surfactants based on linear and branched alcohols are shown in Tables 1-7.

Table 1 Surfactants based on linear C ₁₆ C ₁₈ -alcohols

Table 1 Example As is apparent from the C1 and C3 or C2 and C4, there are several differences between the C ₁₆ C ₁₈ -7PO- sulfates and C ₁₆ C ₁₈ -9PO- sulphate. In this regard, a comparison should be made with a similar T _opt to eliminate the effect of temperature. In the case of surfactants having nonionic elements, these can have a considerable influence.

There is a surprising discovery when C ₁₆ C ₁₈ -alkoxy sulfates containing BuO are used. Examples 5 and 6 are surprising (even at 47 ° C. or 62 ° C.) by introducing two 1,2-butylene oxide units between C ₁₆ C ₁₈ -fatty alcohol and seven propylene oxide units. It shows that stability SP ^* = 16. A similar condition appears at a reduced total surfactant concentration. In Example 11, SP ^* is 15 at 72 ° C. Pure PO-containing compounds with the same degree of alkoxylation show greater changes (variations) (C3 and C4) or SP ^* is somewhat less at the reduced total surfactant concentration. (C9 and C10).

In contrast, the arrangement of 1,2-butylene oxide between the propylene oxide block and the sulfate group, as in Comparative Examples C7 and C8, is not preferred. SP ^* is somewhat lower and varies more greatly to account for different temperatures.

The use of 2,3-butylene oxide is quite bad (poor). As seen in C12, SP ^* = 8 and SP ^* is substantially halved, thus alkoxylation is worse than the same alkylpropoxysulfate (C9). Surprisingly, not only the number of carbons, but also their spatial arrangement has a significant impact on the ability of surfactants to reduce interfacial tension. The undesired configuration, as in the case of 2,3-butylene oxide, has a disruptive effect, and (as compared to the corresponding surfactant that does not have an alkylene oxide with 4 carbon atoms) Give worse values. This is not described in US 3890239 and US 4448697.

Interestingly, when 3 or more 1,2-butylene oxide units are contained in a linear C ₁₆ C ₁₈ -fatty alcohol, an immediate improvement is achieved. In Example 13, the introduction of three such units increases the SP ^* to 23.5. This can be further increased by using 5 units (Examples 14 to 16). Here, SP ^* even exceeds 30.

Table 2 Branched iC ₁₇ -alcohol-based surfactants

A similar situation appears in Table 2. Here, alkyl alkoxy sulfates based on branched iC ₁₇ -alcohols were used to demonstrate (there is an effect that cannot be obtained with linear alcohols alone).

Comparative test C1 and Example 2 show very clearly that it is clearly advantageous to use 1,2-butylene oxide instead of propylene oxide with surfactants of the same degree of alkoxylation. . At similar temperatures, SP ^* is three times higher. Placing 1,2-BuO directly on the alkyl moiety (as in Examples 5 and 6) also provides lower interfacial tension than the different arrangements as in Example 4, for example.

Table 3 Surfactants based on branched C ₁₆ Guerbet alcohol compared to C ₁₆ C ₁₈ -alcohol based surfactants

As can be seen in Table 3, similar conditions apply here. If the surfactant based on linear alcohols contains two or more 1,2-BuO units, a clear jump in SP ^* is seen, and therefore a reduction in interfacial tension is seen. Example 2 compared to Examples 3 and 4 shows the difference between alcohols based on linear C ₁₆ C ₁₈ -alcohols and surfactants based on branched C ₁₆ Guerbet alcohols. In surfactants based on Guerbet, with the introduction of two 1,2-butylene oxide units, a much better SP ^* is already present (than when the surfactant is based on a linear alcohol of similar length). Has been achieved. However, in the case of linear alcohols, an additional introduction of an amount of 1,2-butylene oxide can achieve an SP ^* approximately equal to Example 4, as can be seen in Example 5.

In Example 6, it can be seen that the introduction of 10 EO between the sulfate-based PO blocks can substantially compensate (offset) the additional hydrophobicity of the 7-BuO block; Comparison with Comparative Example C1 can be made under similar conditions (similar salt content, similar temperature T _opt ).

Without the introduction of 1,2-butylene oxide, as can be seen in Comparative Examples C7 and C8, the surfactant is merely an average surfactant. Example 11 shows that the introduction of 1 eq of 1,2-BuO only gives a certain improvement to SP ^* . In the case of C ₁₆ Guerbet-based surfactants (Example 3), only the introduction of 2 eq of 1,2-BuO results in significant improvements.

  Table 4 Tests using South German crude oil

As can be seen in Table 4, a substantially similar situation appears when using crude oil as compared to the test using decane model oil. Comparative Example C1 shows a much lower SP ^* value and thus higher interfacial tension (at comparable temperatures) than the surfactant of Example 2 containing BuO. Comparative Example C3 and Example 4 show the advantage of 1,2-butylene oxide in a similar manner.

  Table 5 Tests using decane at similar temperature and salinity

The aqueous surfactant solution mixed with BDG is clearly soluble under optimal conditions (salinity and T _opt ) and forms a three-phase system (Winsor type III) by adding oil. As shown in Table 5, the optimum conditions (salinity and T _opt ) are very close together. As shown in Example 2, proper adjustment of the degree of alkoxylation results in a surfactant with a hydrophilic-hydrophobic-balance similar to the surfactant in Example V1. SP ^* in Example 2 is very high. As a result, the interfacial tension is very low.

  Table 6 Test using crude oil from Germany (API 33 °) at similar temperature and salinity

The aqueous surfactant solution mixed with BDG is clearly soluble under optimal conditions (salinity and T _opt ) and forms a three-phase system (Winsor type III) by adding oil. As shown in Table 6, the optimum conditions (salinity and T _opt ) are very close together. As shown in Example 2, a suitable adjustment of the degree of alkoxylation results in a surfactant with a hydrophilic-hydrophobic-balance similar to the surfactant in Example V1. The SP ^* in Example 2 is (again) very high. As a result, the interfacial tension is very low.

  Table 7 Test using crude oil from Canada (API 14 °) at similar temperature and salinity

The aqueous surfactant solution mixed with BDG is clearly soluble under optimal conditions (salinity and T _opt ) and forms a three-phase system (Winsor type III) by adding oil. As shown in Table 7, the optimum conditions (salinity and T _opt ) are very close together. As shown in Example 2, a suitable adjustment of the degree of alkoxylation results in a surfactant with a hydrophilic-hydrophobic-balance similar to the surfactant in Example V1. The SP ^* in Example 2 is (again) very high. As a result, the interfacial tension is very low.

Claims (16)

A method for extracting mineral oil using Winsor type III microemulsion flooding, comprising:
In order to reduce the interfacial tension between oil and water to <0.1 mN / m, an aqueous surfactant formulation comprising at least one ionic surfactant is passed through at least one injection hole to form a mineral oil deposit. And injecting the crude oil from the deposit through the at least one production hole;
Wherein the surfactant formulation, the general formula _{^{R 1 -O- (D) n -}} (B) m - (A) l -XY - M +
(However,
R ¹ is a linear or branched, saturated or unsaturated, aliphatic and / or aromatic hydrocarbon group having 8 to 30 carbon atoms,
A is ethyleneoxy,
B is propyleneoxy, and D is butyleneoxy,
l is 0 to 99;
m is 0-99, and n is 1-99,
X is an alkyl or alkylene group having 0 to 10 carbon atoms,
M ⁺ is a cation, and Y ⁻ is selected from the group of sulfate group, sulfonic acid group, carboxylate group, and phosphate group)
At least one surfactant
The groups A, B and D may be randomly or alternately distributed, or 2, 3, 4, or more may be arranged in an arbitrary block, and the sum of l + m + n is A process characterized in that it is in the range 3 to 99 and the proportion of 1,2-butylene oxide is at least 80%, based on the total amount of butylene oxide.   The method of claim 1, wherein the sum of l + m + n is in the range of 5-50.   3. A process according to claim 1, wherein the proportion of 1,2-butylene oxide relative to the total amount of butylene oxide is at least 90%.   The process according to any one of claims 1 to 3, characterized in that the surfactant of the general formula comprises 2 to 15 1,2-butylene oxide units.   5. The concentration of all surfactants combined is 0.05-5% by weight, based on the total amount of aqueous surfactant formulation. The method described in 1. m is 5-9,
n is 2 to 10 and Y ⁻ is selected from the group of sulfate group, sulfonic acid group, carboxylate group, and A, B and D groups are in the range of more than 80% of the given block This block is in the order D, B, A starting from R ¹ , the sum of l + m + n is in the range 7-49, and the proportion of 1,2-butylene oxide is 6. A process according to any one of the preceding claims, characterized in that it is at least 90% with respect to the total amount of butylene oxide. R ¹ is a straight-chain fatty alcohols having 16 or 18 carbon atoms, and methods of claim 6, n is equal to or from 3 to 10. Formula _{^{R 1 -O- (D) n -}} (B) m - (A) l -XY - M +
(However,
R ¹ is a linear or branched, saturated or unsaturated, aliphatic and / or aromatic hydrocarbon group having 8 to 30 carbon atoms,
A is ethyleneoxy,
B is propyleneoxy, and D is butyleneoxy,
l is 0 to 99;
m is 0-99, and n is 1-99,
X is an alkyl or alkylene group having 0 to 10 carbon atoms,
M ⁺ is a cation, and Y ⁻ is selected from the group of sulfate group, sulfonic acid group, carboxylate group, and phosphate group)
At least one ionic surfactant of
The groups A, B and D may be randomly or alternately distributed, or 2, 3, 4, or more may be arranged in an arbitrary block, and the sum of l + m + n is Surfactant formulation, characterized in that it is in the range of 3 to 99 and the proportion of 1,2-butylene oxide is at least 80% relative to the total amount of butylene oxide. m is 5-9, n is 2-10, and Y ⁻ is selected from the group of sulfate groups, sulfonic acid groups, and carboxylate groups, and the A, B, and D groups are More than 80% range exists in a given block state, this block is in the order D, B, A starting from R ¹ , the sum of l + m + n is in the range 7-49, and 1, 9. The surfactant formulation according to claim 8, wherein the proportion of 2-butylene oxide is at least 90% relative to the total amount of butylene oxide in the molecule. R ¹ is, 16 or 18 is a straight-chain fatty alcohols having carbon atoms, and the surfactant formulation of claim 9 which n is equal to or from 3 to 10.   11. The concentration of all surfactants combined is 0.05-5% by weight, based on the total amount of aqueous surfactant formulation. A surfactant formulation as described in 1. Formula _{^{R 1 -O- (A) l -}} (B) m (D) n -XY - M +
(However,
R ¹ is a linear or branched, saturated or unsaturated, aliphatic and / or aromatic hydrocarbon group having 8 to 30 carbon atoms,
A is ethyleneoxy,
B is propyleneoxy, and D is butyleneoxy,
l is 0 to 99;
m is 0-99, and n is 1-99,
X is an alkyl or alkylene group having 0 to 10 carbon atoms,
M ⁺ is a cation, and Y ⁻ is selected from the group of sulfate group, sulfonic acid group, carboxylate group, and phosphate group)
Represented by
The groups A, B and D may be randomly or alternately distributed, or 2, 3, 4, or more may be arranged in an arbitrary block, and the sum of l + m + n is A surfactant, characterized in that it is in the range of 3 to 99 and the proportion of 1,2-butylene oxide is at least 80% relative to the total amount of butylene oxide.   The surfactant according to claim 12, wherein the sum of l + m + n is in the range of 3 to 49.   14. The surfactant according to claim 12, wherein the ratio of 1,2-butylene oxide to the total amount of butylene oxide is at least 90%. R ¹ is a linear or branched, saturated or unsaturated aliphatic and / or aromatic hydrocarbon group having 10 to 30 carbon atoms. The surfactant according to any one of the above. R ¹ is a linear fatty alcohol having 16 or 18 carbon atoms,
m is 5-9, and n is 3-10, and Y ⁻ is selected from the group of sulfate groups, sulfonic acid groups, and carboxylate groups,
The A, B and D groups have more than 80% range in a given block state, this block starting from R ^{1 in} the order D, B, A, and the sum of l + m + n is 7-49 And the proportion of 1,2-butylene oxide is at least 90% with respect to the total amount of butylene oxide in the molecule. .